I think my alternator is bad but unsure

I replaced my battery about two weeks ago. I was having to jump it off every time I would try to start it. It ran solid for those two weeks but two nights ago, I was driving home and my battery light came on, followed by the ABS and Traction Control light, then the air bag light, along with the messages of "Service Traction and air bags", soon after we noticed my headlights were so dim that I was not even sure they were on. Then the power steering went out followed by the interior lights, radio, air conditioner, and my gauges started jumping all over the place. That is when I stopped and called a row truck. It was about 10:30 at night and I still had to drive about forty five miles up the interstate. Again not sure but it seem like maybe a bad alternator but maybe a bad module somewhere? Please help!